8-Substituted imidazopyridines

ABSTRACT

The present invention relates to 8-substituted imidazopyridines of a certain formula (1) 
                         
in which the substitutents and symbols have the meanings indicated in the description. The compounds have gastric secretion inhibiting and excellent gastric and intestinal protective action properties.

TECHNICAL FIELD

The invention relates to novel compounds, which are used in thepharmaceutical industry as active compounds for the production ofmedicaments.

PRIOR ART

In international patent applications WO98/42707 (=U.S. Pat. No.6,197,783), WO98/54188, WO00/17200, WO00/26217, WO00/63211, WO01/72756,WO01/72754, WO01/72755 and WO01/72757, tricyclic imidazopyridinederivatives having a very specific substitution pattern are disclosed,which are said to be suitable for the treatment of gastric andintestinal diseases. In international patent applications WO88/08843,WO89/00570 (=U.S. Pat. No. 5,112,834) and WO90/05136 imidazopyridinederivatives are disclosed, which are likewise said to be suitable forthe treatment of gastric and intestinal diseases

SUMMARY OF THE INVENTION

The invention relates to compounds of the formula 1

in which

-   R1 is hydrogen, 1-4C-alkyl, 3-7C-cycloalkyl,    3-7C-cycloalkyl-1-4C-alkyl, 1-4C-alkoxy, 1-4C-alkoxy-1-4C-alkyl,    1-4C-alkoxycarbonyl, 2-4C-alkenyl, 2-4C-alkynyl, fluoro-1-4C-alkyl    or hydroxy-1-4C-alkyl,-   R2 is hydrogen, 1-4C-alkyl, aryl, 3-7C-cycloalkyl,    3-7C-cycloalkyl-1-4C-alkyl, 1-4C-alkoxycarbonyl, hydroxy-1-4C-alkyl,    halogen, 2-4C-alkenyl, 2-4C-alkynyl, fluoro-1-4C-alkyl,    1-4C-alkyl-aminomethyl or cyanomethyl,-   R3a is hydrogen, halogen, fluoro-1-4C-alkyl, 1-4C-alkyl,    2-4C-alkenyl, 2-4C-alkynyl, carboxyl, —CO-1-4C-alkoxy,    hydroxy-1-4C-alkyl, 1-4C-alkoxy-1-4C-alkyl,    1-4C-alkoxy-1-4C-alkoxy-1-4C-alkyl, fluoro-1-4C-alkoxy-1-4C-alkyl or    the group —CO—NR31R32,-   R3b is hydrogen, halogen, fluoro-1-4C-alkyl, 1-4C-alkyl,    2-4C-alkenyl, 2-4C-alkynyl, carboxyl, —CO-1-4C-alkoxy,    hydroxy-1-4C-alkyl, 1-4C-alkoxy-1-4C-alkyl,    1-4C-alkoxy-1-4C-alkoxy-1-4C-alkyl, fluoro-1-4C-alkoxy-1-4C-alkyl or    the group —CO—NR31R32,    -   where    -   R31 is hydrogen, hydroxyl, 1-7C-alkyl, hydroxy-1-4C-alkyl or        1-4C-alkoxy-1-4C-alkyl and    -   R32 is hydrogen, 1-7C-alkyl, hydroxy-1-4C-alkyl or        1-4C-alkoxy-1-4C-alkyl,    -   or where    -   R31 and R32 together, including the nitrogen atom to which both        are bonded, are a pyrrolidino, piperidino, piperazino,        N-1-4C-alkylpiperazino or morpholino group,-   Z has the meaning —CHR4- or —CHR4-CHR5-    -   where-   R4 is hydrogen, 1-7C-alkyl, 2-7C-alkenyl, hydroxyl, 1-4C-alkoxy,    oxo-substituted 1-4C-alkoxy, 3-7C-cycloalkoxy,    3-7C-cycloalkyl-1-4C-alkoxy, hydroxy-1-4C-alkoxy,    1-4C-alkoxy-1-4C-alkoxy, 1-4C-alkoxy-1-4C-alkoxy-1-4C-alkoxy,    3-7C-cycloalkoxy-1-4C-alkoxy,    3-7C-cycloalkyl-1-4C-alkoxy-1-4C-alkoxy, 1-4C-alkylcarbonyloxy,    halo-1-4C-alkoxy, amino, mono- or di-1-4C-alkylamino,    1-4C-alkylcarbonylamino, 1-4C-alkoxycarbonylamino, mono- or    di-1-4C-alkylamino-1-4C-alkylcarbonyloxy or    1-4C-alkoxy-1-4C-alkoxycarbonylamino,-   R5 is hydrogen, 1-7C-alkyl, 2-7C-alkenyl, hydroxyl, 1-4C-alkoxy,    oxo-substituted 1-4C-alkoxy, 3-7C-cycloalkoxy,    3-7C-cycloalkyl-1-4C-alkoxy, hydroxy-1-4C-alkoxy,    1-4C-alkoxy-1-4C-alkoxy, 1-4C-alkoxy-1-4C-alkoxy-1-4C-alkoxy,    3-7C-cycloalkoxy-1-4C-alkoxy,    3-7C-cycloalkyl-1-4C-alkoxy-1-4C-alkoxy, 1-4C-alkylcarbonyloxy,    halo-1-4C-alkoxy, amino, mono- or di-1-4C-alkylamino,    1-4C-alkylcarbonylamino, 1-4C-alkoxycarbonylamino, mono- or    di-1-4C-alkylamino-1-4C-alkylcarbonyloxy or    1-4C-alkoxy-1-4C-alkoxycarbonylamino,-   R6 is hydrogen, 1-4C-alkyl, hydroxy-1-4C-alkyl, 1-4C-alkoxy,    1-4C-alkoxy-1-4C-alkyl, 2-4C-alkenyloxy, 1-4C-alkylcarbonyl,    carboxyl, 1-4C-alkoxycarbonyl, carboxy-1-4C-alkyl,    1-4C-alkoxycarbonyl-1-4C-alkyl, halogen, hydroxyl, trifluoromethyl,    nitro, amino, mono- or di-1-4C-alkylamino, 1-4C-alkylcarbonylamino,    1-4C-alkoxycarbonylamino, 1-4C-alkoxy-1-4C-alkoxycarbonylamino or    sulfonyl,-   R7 is hydrogen, 1-4C-alkyl, 1-4C-alkoxy, 1-4C-alkoxycarbonyl,    halogen, trifluoromethyl or hydroxyl,-   X is O (oxygen) or NH, and-   aryl is phenyl or substituted phenyl having one, two or three    identical or different substituents from the group consisting of    1-4C-alkyl, 1-4C-alkoxy, carboxyl, 1-4C-alkoxycarbonyl, halogen,    trifluoromethyl, nitro, trifluoromethoxy, hydroxyl and cyano,    and their salts, with the provisos that    -   (1) R3a is not hydrogen, halogen, 1-4C-alkoxy or —CO-1-4C-alkoxy        when R3b is hydrogen, Z has the meaning —CHR4- and R4 is        hydrogen or 1-7C-alkyl,    -   (2) R3a is not hydrogen, halogen, 1-4C-alkoxy or —CO-1-4C-alkoxy        when R3b is hydrogen, Z has the meaning —CHR4-CHR5-, R4 is        hydrogen or 1-7C-alkyl and R5 is hydrogen or 1-7C-alkyl,    -   (3) R3a is not hydrogen or halogen when R3b is hydrogen, Z has        the meaning —CHR4- and R4 is hydroxyl,    -   (4) R3a is not hydrogen or halogen when R3b is hydrogen, Z has        the meaning —CHR4-CHR5-, one of R4 and R5 is hydroxyl and the        other is hydrogen or 1-7C-alkyl,    -   (5) R3a is not hydrogen when R3b is hydrogen, X is O (oxygen), Z        has the meaning —CHR4- and R4 is 1-4C-alkoxy, 3-7C-cycloalkoxy,        1-4C-alkoxy-1-4C-alkoxy or 1-4C-alkylcarbonyloxy and    -   (6) R3a is not hydrogen when R3b is hydrogen, X is O (oxygen), Z        has the meaning —CHR4-CHR5-, one of R4 and R5 1-4C-alkoxy,        3-7C-cycloalkoxy, 1-4C-alkoxy-4C-alkoxy or 1-4C-alkylcarbonyloxy        and the other is hydrogen.

1-4C-Alkyl represents straight-chain or branched alkyl groups having 1to 4 carbon atoms. Examples which may be mentioned are the butyl,isobutyl, sec-butyl, tert-butyl, propyl, isopropyl, ethyl and the methylgroup.

3-7C-Cycloalkyl represents cyclopropyl, cyclobutyl, cyclopentyl,cyclohexyl and cycloheptyl, of which cyclopropyl, cyclobutyl andcyclopentyl are preferred.

3-7C-Cycloalkyl-1-4C-alkyl represents one of the aforementioned1-4C-alkyl groups, which is substituted by one of the aforementioned3-7C-cycloalkyl groups. Examples which may be mentioned are thecyclopropylmethyl, the cyclohexylmethyl and the cyclohexylethyl group.

1-4C-Alkoxy represents groups, which in addition to the oxygen atomcontain a straight-chain or branched alkyl group having 1 to 4 carbonatoms. Examples which may be mentioned are the butoxy, isobutoxy,sec-butoxy, tert-butoxy, propoxy, isopropoxy and preferably the ethoxyand methoxy group.

1-4C-Alkoxy-1-4C-alkyl represents one of the aforementioned 1-4C-alkylgroups, which is substituted by one of the aforementioned 1-4C-alkoxygroups. Examples which may be mentioned are the methoxymethyl, themethoxyethyl group and the butoxyethyl group.

1-4C-Alkoxycarbonyl (—CO-1-4C-alkoxy) represents a carbonyl group, towhich one of the aforementioned 1-4C-alkoxy groups is bonded. Exampleswhich may be mentioned are the methoxycarbonyl (CH₃O—C(O)—) and theethoxycarbonyl group (CH₃CH₂O—C(O)—).

2-4C-Alkenyl represents straight-chain or branched alkenyl groups having2 to 4 carbon atoms. Examples which may be mentioned are the 2-butenyl,3-butenyl, 1-propenyl and the 2-propenyl group (allyl group).

2-4C-Alkynyl represents straight-chain or branched alkynyl groups having2 to 4 carbon atoms. Examples which may be mentioned are the 2-butynyl,3-butynyl, and preferably the 2-propynyl, group (propargyl group).

Fluoro-1-4C-alkyl represents one of the aforementioned 1-4C-alkylgroups, which is substituted by one or more fluorine atoms. An examplewhich may be mentioned is the trifluoromethyl group.

Hydroxy-1-4C-alkyl represents aforementioned 1-4C-alkyl groups, whichare substituted by a hydroxy group. Examples which may be mentioned arethe hydroxymethyl, the 2-hydroxyethyl and the 3-hydroxypropyl group.

Halogen within the meaning of the invention is bromo, chloro and fluoro.

1-4-Alkoxy-1-4C-alkoxy represents one of the aforementioned 1-4C-alkoxygroups, which is substituted by a further 1-4C-alkoxy group. Exampleswhich may be mentioned are the groups 2-(methoxy)ethoxy(CH₃—O—CH₂—CH₂—O—) and 2-(ethoxy)ethoxy (CH₃—CH₂—O—CH₂—CH₂—O—).

1-4C-Alkoxy-1-4C-alkoxy-1-4C-alkyl represents one of the aforementioned1-4C-alkoxy-1-4C-alkyl groups, which is substituted by one of theaforementioned 1-4C-alkoxy groups. An example which may be mentioned isthe group 2-(methoxy)ethoxymethyl (CH₃—O—CH₂—CH₂—O—CH₂—).

Fluoro-1-4C-alkoxy-1-4C-alkyl represents one of the aforementioned1-4C-alkyl groups, which is substituted by a fluoro-1-4C-alkoxy group.Fluoro-1-4C-alkoxy in this case represents one of the aforementioned1-4C-alkoxy groups, which is completely or mainly substituted byfluorine. Examples of completely or mainly fluoro-substituted1-4C-alkoxy groups which may be mentioned are the1,1,1,3,3,3-hexafluoro-2-propoxy, the 2-trifluoromethyl-2-propoxy, the1,1,1-trifluoro-2-propoxy, the perfluoro-tert-butoxy, the2,2,3,3,4,4,4-heptafluoro-1-butoxy, the 4,4,4-trifluoro-1-butoxy, the2,2,3,3,3-pentafluoropropoxy, the perfluoroethoxy, the1,2,2-trifluoroethoxy, in particular the 1,1,2,2-tetrafluoroethoxy, the2,2,2-trifluoroethoxy, the trifluoromethoxy and preferably thedifluoromethoxy group.

1-7C-Alkyl represents straight-chain or branched alkyl groups having 1to 7 carbon atoms. Examples which may be mentioned are the heptyl,isoheptyl (5-methylhexyl), hexyl, isohexyl (4-methylpentyl), neohexyl(3,3-dimethylbutyl), pentyl, isopentyl (3-methylbutyl), neopentyl(2,2-dimethylpropyl), butyl, isobutyl, sec-butyl, tert-butyl, propyl,isopropyl, ethyl and the methyl group.

2-7C-Alkenyl represents straight-chain or branched alkenyl groups having2 to 7 carbon atoms. Examples which may be mentioned are the 2-butenyl,3-butenyl, 1-propenyl, the 2-propenyl (allyl) and the vinyl group. Theaforementioned 2-4C-alkenyl groups are preferred.

Oxo-substituted 1-4C-alkoxy represents a 1-4C-alkoxy group, whichinstead of a methylene group contains a carbonyl group. An example whichmay be mentioned is the 2-oxopropoxy group.

3-7C-Cycloalkoxy represents cyclopropyloxy, cyclobutyloxy,cyclopentyloxy, cyclohexyloxy and cycloheptyloxy, of whichcyclopropyloxy, cyclobutyloxy and cyclopentyloxy are preferred.

3-7C-Cycloalkyl-1-4C-alkoxy represents one of the aforementioned1-4C-alkoxy groups, which is substituted by one of the aforementioned3-7C-cycloalkyl groups. Examples which may be mentioned are thecyclopropylmethoxy, the cyclobutylmethoxy and the cyclohexylethoxygroup.

Hydroxy-1-4C-alkoxy represents aforementioned 1-4C-alkoxy groups, whichare substituted by a hydroxy group. A preferred example which may bementioned is the 2-hydroxyethoxy group.

1-4C-Alkoxy-1-4C-alkoxy-1-4C-alkoxy represents one of the aforementioned1-4C-alkoxy groups, which is substituted by one of the aforementioned1-4C-alkoxy-1-4C-alkoxy groups. A preferred example which may bementioned is the methoxyethoxyethoxy group.

3-7C-Cycloalkoxy-1-4C-alkoxy represents one of the aforementioned1-4C-alkoxy groups, which is substituted by one of the aforementioned3-7C-cycloalkoxy groups. Examples which may be mentioned are thecyclopropoxymethoxy, the cyclobutoxymethoxy and the cyclohexyloxyethoxygroup.

3-7C-Cycloalkyl-1-4C-alkoxy-1-4C-alkoxy represents one of theaforementioned 1-4C-alkoxy groups, which is substituted by one of theaforementioned 3-7C-cycloalkyl-1-4C-alkoxy groups. Examples which may bementioned are the cyclopropylmethoxyethoxy, the cyclobutylmethoxyethoxyand the cyclohexylethoxyethoxy group.

1-4C-Alkylcarbonyl represents a group, which in addition to the carbonylgroup contains one of the aforementioned 1-4C-alkyl groups. An examplewhich may be mentioned is the acetyl group.

1-4C-Alkylcarbonyloxy represents a 1-4C-alkylcarbonyl group which isbonded to an oxygen atom. An example which may be mentioned is theacetoxy group (CH₃CO—O—).

Halo-1-4C-alkoxy represents 1-4C-alkoxy groups which are completely ormainly substituted by halogen. “Mainly” in this connection means thatmore than half of the hydrogen atoms in the 1-4C-alkoxy groups arereplaced by halogen atoms. Halo-1-4C-alkoxy groups are primarily chloro-and/or in particular fluoro-substituted 1-4C-alkoxy groups. Examples ofhalogen-substituted 1-4C-alkoxy groups which may be mentioned are the2,2,2-trichloroethoxy, the hexachloroisopropoxy, thepentachloroisopropoxy, the 1,1,1-trichloro-3,3,3-trifluoro-2-propoxy,the 1,1,1-trichloro-2-methyl-2-propoxy, the 1,1,1-trichloro-2-propoxy,the 3-bromo-1,1,1-trifluoro-2-propoxy, the3-bromo-1,1,1-trifluoro-2-butoxy, the4-bromo-3,3,4,4-tetrafluoro-1-butoxy, the chlorodifluoromethoxy, the1,1,1,3,3,3-hexafluoro-2-propoxy, the 2-trifluoromethyl-2-propoxy, the1,1,1-trifluoro-2-propoxy, the perfluoro-tert-butoxy, the2,2,3,3,4,4,4-heptafluoro-1-butoxy, the 4,4,4-trifluoro-1-butoxy, the2,2,3,3,3-pentafluoropropoxy, the perfluoroethoxy, the1,2,2-trifluoroethoxy, in particular the 1,1,2,2-tetrafluoroethoxy, the2,2,2-trifluoroethoxy, the trifluoromethoxy and preferably thedifluoromethoxy group.

Mono- or di-1-4C-alkylamino represents an amino group, which issubstituted by one or by two—identical or different—groups from theaforementioned 1-4C-alkyl groups. Examples which may be mentioned arethe dimethylamino, the diethylamino and the diisopropylamino group.

1-4C-Alkylcarbonyl represents a group, which in addition to the carbonylgroup contains one of the aforementioned 1-4C-alkyl groups. An examplewhich may be mentioned is the acetyl group.

1-4C-Alkylcarbonylamino represents an amino group to which a1-4C-alkylcarbonyl group is bonded. Examples which may be mentioned arethe propionylamino (C₃H₇C(O)NH—) and the acetylamino group (acetamidogroup) (CH₃C(O)NH—).

1-4C-Alkoxycarbonylamino represents an amino group, which is substitutedby one of the aforementioned 1-4C-alkoxycarbonyl groups. Examples, whichmay be mentioned, are the ethoxycarbonylamino and themethoxycarbonylamino group.

Mono- or di-1-4C-alkylamino-1-4C-alkylcarbonyloxy represents a1-4C-alkylcarbonyloxy group, which is substituted by one of theaforementioned mono- or di-1-4C-alkylamino groups. Examples, which maybe mentioned, are the dimethylamino-methylcarbonyloxy and thedimethylamino-ethylcarbonyloxy group.

1-4C-Alkoxy-1-4C-alkoxycarbonyl represents a carbonyl group, to whichone of the aforementioned 1-4C-alkoxy-1-4C-alkoxy groups is bonded.Examples which may be mentioned are the 2-(methoxy)-ethoxycarbonyl(CH₃—O—CH₂CH₂—O—CO—) and the 2-(ethoxy)ethoxycarbonyl group(CH₃CH₂—O—CH₂CH₂—O—CO—).

1-4C-Alkoxy-1-4C-alkoxycarbonylamino represents an amino group, which issubstituted by one of the aforementioned 1-4C-alkoxy-1-4C-alkoxycarbonylgroups. Examples which may be mentioned are the2-(methoxy)ethoxycarbonylamino and the 2-(ethoxy)ethoxycarbonylaminogroup.

2-4C-Alkenyloxy represents groups, which in addition to the oxygen atomcontain one of the above-mentioned 2-4C-alkenyl groups. Examples, whichmay be mentioned, are the 2-butenyloxy, 3-butenyloxy, 1-propenyloxy andthe 2-propenyloxy group (allyloxy group).

Carboxy-1-4C-alkyl represents 1-4C-alkyl groups which are substituted bya carboxyl group. Examples, which may be mentioned, are thecarboxymethyl and the 2-carboxyethyl group.

1-4C-Alkoxycarbonyl-1-4C-alkyl represents 1-4C-alkyl groups, which aresubstituted by one of the abovementioned 1-4C-alkoxycarbonyl groups.Examples, which may be mentioned, are the methoxycarbonylmethyl and theethoxycarbonylmethyl group.

Possible salts of compounds of the formula I—depending onsubstitution—are especially all acid addition salts. Particular mentionmay be made of the pharmacologically tolerable salts of the inorganicand organic acids customarily used in pharmacy. Those suitable arewater-soluble and water-insoluble acid addition salts with acids suchas, for example, hydrochloric acid, hydrobromic acid, phosphoric acid,nitric acid, sulfuric acid, acetic acid, citric acid, D-gluconic acid,benzoic acid, 2-(4-hydroxybenzoyl)-benzoic acid, butyric acid,sulfosalicylic acid, maleic acid, lauric acid, malic acid, fumaric acid,succinic acid, oxalic acid, tartaric acid, embonic acid, stearic acid,toluenesulfonic acid, methanesulfonic acid or 3-hydroxy-2-naphthoicacid, where the acids are used in salt preparation—depending on whethera mono- or polybasic acid is concerned and on which salt is desired—inan equimolar quantitative ratio or one differing there from.

Pharmacologically intolerable salts, which can initially be obtained,for example, as process products in the production of the compoundsaccording to the invention on the industrial scale, are converted intothe pharmacologically tolerable salts by processes known to the personskilled in the art.

It is known to the person skilled in the art that the compoundsaccording to invention and their salts, if, for example, they areisolated in crystalline form, can contain various amounts of solvents.The invention therefore also comprises all solvates and in particularall hydrates of the compounds of the formula I, and also all solvatesand in particular all hydrates of the salts of the compounds of theformula I.

The compounds of the formula I have up to three chiral centres in theparent structure. The invention thus relates to all conceivablestereoisomers in any desired mixing ratio to one another, including thepure enantiomers, which are a preferred subject of the invention.

One embodiment (embodiment 1) of the invention are compounds of theformula 1, in which

-   Z has the meaning —CHR4-    and their salts.

The compounds of embodiment 1 are characterized by the following formula1-1

in which R1, R2, R3a, R3b, R4, R6, R7 and X have the abovementionedmeanings.

Another embodiment (embodiment 2) of the invention are compounds of theformula 1, in which

-   Z has the meaning —CHR4-CHR5-    and their salts.

The compounds of embodiment 2 are characterized by the following formula1-2

in which R1, R2, R3a, R3b, R4, R5, R6, R7 and X have the abovementionedmeanings.

Compounds to be emphasized are those of the formula 1, in which

-   R1 is hydrogen, 1-4C-alkyl, 3-7C-cycloalkyl, 1-4C-alkoxy-1-4C-alkyl,    2-4C-alkynyl or fluoro-1-4C-alkyl,-   R2 is hydrogen, 1-4C-alkyl, hydroxy-1-4C-alkyl, halogen,    2-4C-alkenyl, 2-4C-alkynyl or fluoro-1-4C-alkyl,-   R3a is in the 6-position and denotes fluoro-1-4C-alkyl, 1-4C-alkyl,    2-4C-alkenyl, 2-4C-alkynyl, carboxyl, —CO-1-4C-alkoxy,    hydroxy-1-4C-alkyl, 1-4C-alkoxy-1-4C-alkyl,    1-4C-alkoxy-1-4C-alkoxy-1-4C-alkyl, fluoro-1-4C-alkoxy-1-4C-alkyl or    the group —CO—NR31R32,    -   where    -   R31 is hydrogen, hydroxyl, 1-7C-alkyl, hydroxy-1-4C-alkyl or        1-4C-alkoxy-1-4C-alkyl and    -   R32 is hydrogen, 1-7C-alkyl, hydroxy-1-4C-alkyl or        1-4C-alkoxy-1-4C-alkyl,    -   or where    -   R31 and R32 together, including the nitrogen atom to which both        are bonded, are a pyrrolidino, piperidino, piperazino,        N-1-4C-alkylpiperazino or morpholino group,-   R3b is hydrogen,-   Z has the meaning —CHR4- or —CHR4-CHR5-    -   where-   R4 is hydroxyl, 1-4C-alkoxy, oxo-substituted 1-4C-alkoxy,    3-7C-cycloalkoxy, 3-7C-cycloalkyl-1-4C-alkoxy, hydroxy-1-4C-alkoxy,    1-4C-alkoxy-1-4C-alkoxy, 1-4C-alkoxy-1-4C-alkoxy-1-4C-alkoxy,    3-7C-cycloalkoxy-1-4C-alkoxy,    3-7C-cycloalkyl-1-4C-alkoxy-1-4C-alkoxy, 1-4C-alkylcarbonyloxy,    halo-1-4C-alkoxy, amino, mono- or di-1-4C-alkylamino,    1-4C-alkylcarbonylamino, 1-4C-alkoxycarbonylamino, mono- or    di-1-4C-alkylamino-1-4C-alkylcarbonyloxy or    1-4C-alkoxy-1-4C-alkoxycarbonylamino,-   R5 is hydrogen, 1-7C-alkyl, 2-7C-alkenyl, hydroxyl, 1-4C-alkoxy,    oxo-substituted 1-4C-alkoxy, 3-7C-cycloalkoxy,    3-7C-cycloalkyl-1-4C-alkoxy, hydroxy-1-4C-alkoxy,    1-4C-alkoxy-1-4C-alkoxy, 1-4C-alkoxy-1-4C-alkoxy-1-4C-alkoxy,    3-7C-cycloalkoxy-1-4C-alkoxy,    3-7C-cycloalkyl-1-4C-alkoxy-1-4C-alkoxy, 1-4C-alkylcarbonyloxy,    halo-1-4C-alkoxy, amino, mono- or di-1-4C-alkylamino,    1-4C-alkylcarbonylamino, 1-4C-alkoxycarbonylamino, mono- or    di-1-4C-alkylamino-1-4C-alkylcarbonyloxy or    1-4C-alkoxy-1-4C-alkoxycarbonylamino,-   R6 is hydrogen, 1-4C-alkyl, hydroxy-1-4C-alkyl, 1-4C-alkoxy,    1-4C-alkoxy-1-4C-alkyl, 2-4C-alkenyloxy, 1-4C-alkylcarbonyl,    carboxyl, 1-4C-alkoxycarbonyl, carboxy-1-4C-alkyl,    1-4C-alkoxycarbonyl-1-4C-alkyl, halogen, hydroxyl, trifluoromethyl,    nitro, amino, mono- or di-1-4C-alkylamino, 1-4C-alkylcarbonylamino,    1-4C-alkoxycarbonylamino, 1-4C-alkoxy-1-4C-alkoxycarbonylamino or    sulfonyl,-   R7 is hydrogen, 1-4C-alkyl, 1-4C-alkoxy, 1-4C-alkoxycarbonyl,    halogen, trifluoromethyl or hydroxyl,-   X is O (oxygen) or NH,    and their salts.

Compounds to be particularly emphasized are those of the formula 1, inwhich

-   R1 is 1-4C-alkyl,-   R2 is hydrogen, 1-4C-alkyl or halogen,-   R3a is in the 6-position and denotes carboxyl, —CO-1-4C-alkoxy,    hydroxy-1-4C-alkyl, 1-4C-alkoxy-1-4C-alkyl or the group —CO—NR31R32,    -   where    -   R31 is hydrogen, 1-7C-alkyl, hydroxy-1-4C-alkyl or        1-4C-alkoxy-1-4C-alkyl and    -   R32 is hydrogen, 1-7C-alkyl, hydroxy-1-4C-alkyl or        1-4C-alkoxy-1-4C-alkyl,    -   or where    -   R31 and R32 together, including the nitrogen atom to which both        are bonded, are a pyrrolidino, piperidino, piperazino,        N-1-4C-alkylpiperazino or morpholino group,-   R3b is hydrogen,-   Z has the meaning —CHR4- or —CHR4-CHR5-    -   where-   R4 is hydroxyl,-   R5 is hydrogen,-   R6 is hydrogen, 1-4C-alkyl or 1-4C-alkoxy,-   R7 is hydrogen,-   X is O (oxygen) or NH,    and their salts.

Compounds of embodiment 1 to be particularly emphasized are those of theformula 1-1, in which

-   R1 is 1-4C-alkyl,-   R2 is hydrogen, 1-4C-alkyl or halogen,-   R3a is in the 6-position and denotes carboxyl, —CO-1-4C-alkoxy,    hydroxy-1-4C-alkyl, 1-4C-alkoxy-1-4C-alkyl or the group —CO—NR31R32,    -   where    -   R31 is hydrogen, 1-7C-alkyl, hydroxy-1-4C-alkyl or        1-4C-alkoxy-1-4C-alkyl and    -   R32 is hydrogen, 1-7C-alkyl, hydroxy-1-4C-alkyl or        1-4C-alkoxy-1-4C-alkyl,    -   or where    -   R31 and R32 together, including the nitrogen atom to which both        are bonded, are a pyrrolidino, piperidino, piperazino,        N-1-4C-alkylpiperazino or morpholino group,-   R3b is hydrogen,-   R4 is hydroxyl,-   R6 is hydrogen, 1-4C-alkyl or 1-4C-alkoxy,-   R7 is hydrogen,-   X is O (oxygen) or NH,    and their salts.

Among the compounds of embodiment 1, the optically pure compounds of theformula 1-1*

are preferred.

Among the compounds of embodiment 2, the optically pure compounds of theformula 1-2*

are preferred.

Preferred exemplary compounds of the formula 1-2* are those, in which

-   R1 is 1-4C-alkyl,-   R2 is 1-4C-alkyl,-   R3a is in the 6-position and denotes carboxyl, —CO-1-4C-alkoxy,    1-4C-alkoxy-1-4C-alkyl or the group —CO—NR31R32,    -   where    -   R31 is hydrogen, 1-4C-alkyl, hydroxy-1-4C-alkyl or        1-4C-alkoxy-1-4C-alkyl and    -   R32 is hydrogen or 1-4C-alkyl,-   R4 is hydroxyl,-   R5 is hydrogen,-   R6 is hydrogen,-   R7 is hydrogen,-   X is O (oxygen) or NH,    and their salts.

Selected particularly preferred compounds of the formula 1-2* are those,in which

-   R1 is 1-4C-alkyl,-   R2 is 1-4C-alkyl,-   R3a is in the 6-position and denotes the group —CO—NR31R32,    -   where    -   R31 is hydrogen, 1-4C-alkyl or 1-4C-alkoxy-1-4C-alkyl and    -   R32 is hydrogen or 1-4C-alkyl,-   R4 is hydroxyl,-   R5 is hydrogen,-   R6 is hydrogen,-   R7 is hydrogen,-   X is O (oxygen),    and their salts.

Preferred compounds are those of embodiment 1.

Preferred exemplary compounds of the formula 1-1* are accordingly those,in which

-   R1 is 1-4C-alkyl,-   R2 is hydrogen, 1-4C-alkyl or halogen,-   R3a is in the 6-position and denotes carboxyl, —CO-1-4C-alkoxy,    1-4C-alkoxy-1-4C-alkyl, 1-4C-alkoxy-1-4C-alkoxy-1-4C-alkyl or the    group —CO—NR31R32,    -   where    -   R31 is hydrogen, 1-7C-alkyl, hydroxy-1-4C-alkyl or        1-4C-alkoxy-1-4C-alkyl and    -   R32 is hydrogen, 1-7C-alkyl, hydroxy-1-4C-alkyl or        1-4C-alkoxy-1-4C-alkyl,    -   or where    -   R31 and R32 together, including the nitrogen atom to which both        are bonded, are a pyrrolidino, piperidino, piperazino,        N-1-4C-alkylpiperazino or morpholino group,-   R4 is hydroxyl, 1-4C-alkoxy, oxo-substituted 1-4C-alkoxy,    3-7C-cycloalkoxy, 3-7C-cycloalkyl-1-4C-alkoxy, hydroxy-1-4C-alkoxy,    1-4C-alkoxy-1-4C-alkoxy, 1-4C-alkoxy-1-4C-alkoxy-1-4C-alkoxy,    3-7C-cycloalkoxy-1-4C-alkoxy,    3-7C-cycloalkyl-1-4C-alkoxy-1-4C-alkoxy, 1-4C-alkylcarbonyloxy,    halo-1-4C-alkoxy, amino, mono- or di-1-4C-alkylamino,    1-4C-alkylcarbonylamino, 1-4C-alkoxycarbonylamino, mono- or    di-1-4C-alkylamino-1-4C-alkylcarbonyloxy or    1-4C-alkoxy-1-4C-alkoxycarbonylamino,-   R6 is hydrogen, 1-4C-alkyl, 1-4C-alkoxy or halogen,-   R7 is hydrogen,-   X is O (oxygen) or NH, and their salts.

Particularly preferred compounds of the formula 1-1* are those, in which

-   R1 is 1-4C-alkyl,-   R2 is 1-4C-alkyl,-   R3a is in the 6-position and denotes carboxyl, —CO-1-4C-alkoxy,    1-4C-alkoxy-1-4C-alkyl or the group —CO—NR31R32,    -   where    -   R31 is hydrogen, 1-4C-alkyl, hydroxy-1-4C-alkyl or        1-4C-alkoxy-1-4C-alkyl and    -   R32 is hydrogen or 1-4C-alkyl,-   R4 is hydroxyl,-   R6 is hydrogen,-   R7 is hydrogen,-   X is O (oxygen) or NH,    and their salts.

Selected particularly preferred compounds of the formula 1-1* are those,in which

-   R1 is 1-4C-alkyl,-   R2 is 1-4C-alkyl,-   R3a is in the 6-position and denotes the group —CO—NR31R32,    -   where    -   R31 is hydrogen, 1-4C-alkyl or 1-4C-alkoxy-1-4C-alkyl and    -   R32 is hydrogen or 1-4C-alkyl,-   R4 is hydroxyl,-   R6 is hydrogen, 1-4C-alkyl or 1-4C-alkoxy,-   R7 is hydrogen,-   X is O (oxygen) or NH,    and their salts.

Within the selected particularly preferred compounds of the formula1-1*, those in which X is O (oxygen) have to be singled out.

Particularly preferred exemplary compounds are those of formula 1-1* inwhich R1 is methyl, R6 is hydrogen, R7 is hydrogen and the substituentsand groups R2, R3a (in 6-position), R4 and X have the meanings given inthe following table 1,

TABLE 1 R2 R3a R4 X CH₃ CON(CH₃)₂ OH NH H CON(CH₃)₂ OH NH Cl CON(CH₃)₂OH NH CH₃ CONH₂ OH NH H CONH₂ OH NH Cl CONH₂ OH NH CH₃ CON(CH₃)₂ OH O HCON(CH₃)₂ OH O Cl CON(CH₃)₂ OH O CH₃ CONH₂ OH O H CONH₂ OH O Cl CONH₂ OHO CH₃ CONHCH₂CH₂OH OH NH H CONHCH₂CH₂OH OH NH Cl CONHCH₂CH₂OH OH NH CH₃CH₂OCH₃ OH NH H CH₂OCH₃ OH NH Cl CH₂OCH₃ OH NH CH₃ CONHCH₂CH₂OH OH O HCONHCH₂CH₂OH OH O Cl CONHCH₂CH₂OH OH O CH₃ CH₂OCH₃ OH O H CH₂OCH₃ OH OCl CH₂OCH₃ OH Oand the salts of these compounds.

Particularly preferred are the compounds given as final products in theexamples, and the salts of these compounds.

The compounds according to the invention can be synthesised fromcorresponding starting compounds, for example according to the reactionschemes given below. The synthesis is carried out in a manner known tothe expert, for example as described in more detail in the followingexamples.

The starting compounds are known, for example from WO99/55706 (e.g.methyl 8-amino-2,3-dimethylimidazo[1,2-a]pyridine-6-carboxylate),WO01/72754 (e.g. ethyl8-benzyloxy-2,3-dimethyl-imidazo[1,2-a]pyridine-6-carboxylate) orWO01/72757 (e.g.8-benzyloxy-6-methoxymethyl-2,3-dimethylimidazo[1,2-a]pyridine) or theycan be prepared using analogous process steps. 1,2-Epoxyindane isdescribed for example in W. F. Whitmore; A. I. Gebhart, J. Am. Chem.Soc. 1942, 64, 912; for enantiomeric pure 1,2-epoxyindane see e.g. D. R.Boyd; N. D. Sharma; A. E. Smith, J. Chem. Soc. Perkin Trans. I 1982,2767. In general, substituted alkyl-, alkoxy- or halogeno-epoxyindanescan be prepared from the corresponding substituted indenes by methodsknown from literature (e.g. epoxidation) or by the general method knownto the expert as depicted in scheme 1.

The reaction steps outlined above are carried out in a manner known perse, e.g. as described in more detail in the examples. Thederivatization, if any, of the compounds obtained according to the aboveScheme 2 (e.g. conversion of a group R3a into another group R3a, orconversion of the hydroxyl group into an alkoxy or ester group) islikewise carried out in a manner known per se, e.g. as described by wayof example in international patent applications WO 00/17200 andWO01/72757. If compounds where R3a=—CO—NR31R32 are desired, anappropriate derivatization can be performed in a manner known per se(conversion of an ester into an amide) at the stage of the8-benzyloxy-6-ethoxycarbonyl compound (cf. WO 01/72757) or after thedebenzylation/reduction, or alternatively also at a later point in time.The debenzylation/reduction itself is likewise carried out in a mannerknown per se, for example using hydrogen/Pd(0).

Starting compounds having various substituents R1 and R2 are known, orthey can be prepared in a known manner in analogy to known compounds.Alternatively, derivatizations—for example at position 3—can also becarried out at the stage of the compounds 1. It is thus possible, forexample, starting from compounds where R2=H, to prepare compounds whereR2=CH₂OH (by Vilsmeier reaction and subsequent reduction), where R2=Clor Br (by chlorination or bromination), where R2=propynyl (from thecorresponding bromo compound using the Sonogashira reaction) or whereR2=alkoxycarbonyl (from the corresponding bromo compound by metalcatalysed carbonylation).

The following examples serve to illustrate the invention in greaterdetail without restricting it. Likewise, further compounds of theformula 1 whose preparation is not described explicitly can be preparedin an analogous manner or in a manner familiar per se to the personskilled in the art using customary process techniques. The abbreviationmin stands for minute(s), h for hour(s).

EXAMPLES 1. Methyl8-(trans-2,3-dihydro-2-hydroxy-1-indenylamino)-2,3-dimethyl-imidazo[1,2-a]pyridine-6-carboxylate

10.0 g (45.7 mmol) methyl8-amino-2,3-dimethylimidazo[1,2-a]pyridine-6-carboxylate and 18.1 g (137mmol) 1,2-epoxyindane are suspended in 300 ml dioxane and 100 ml water.The reaction mixture is stirred at 100° C. for 2.5 d. After cooling downin an ice bath, the precipitate is collected and washed with water. Theproduct is suspended in a mixture of 2-propanol and acetone (1:1) andfiltered by suction. After drying in vacuo at 50° C., 12.4 g (77%) ofthe title compound are isolated as a colourless solid (m.p. 261-262°C.).

2.8-(trans-2,3-Dihydro-2-hydroxy-1-indenylamino)-2,3-dimethyl-imidazo[1,2-a]pyridine-6-carboxylicacid

2.0 g (5.7 mmol) methyl8-(trans-2,3-dihydro-2-hydroxy-1-indenylamino)-2,3-dimethyl-imidazo[1,2-a]pyridine-6-carboxylateare suspended in 100 ml dioxane and 20 ml 2N aqueous sodium hydroxideand heated to reflux. After 1 h the reaction mixture is cooled down,evaporated in vacuo to ¼ of its volume and 50 ml water are added. The pHof the mixture is adjusted to pH=7 by adding 2N hydrochloric acid andthe flask is placed in an ice bath. After 30 min, the precipitate iscollected, washed with water and dried in vacuo at 50° C. to yield 1.4 g(73%) of the title compound (m.p. 246-249° C.).

3.8-(trans-2,3-Dihydro-2-hydroxy-1-indenylamino)-6-[N-(2-methoxyethyl)-amino-carbony]-2,3-dimethyl-imidazol-[1,2-a]pyridine

1.4 g (4.1 mmol)8-(trans-2,3-dihydro-2-hydroxy-1-indenylamino)-2,3-dimethyl-imidazo[1,2-a]pyridine-6-carboxylicacid and 1.7 g (5.3 mmol)O-(1H-benzotriazol-1-yl)-N,N,N′,N′-tetramethyluronium tetrafluoroborate(TBTU) are suspended in 100 ml dichloromethane. After stirring for 20min, 0.71 ml (8.2 mmol) 2-methoxyethylamine are added to the reactionmixture. After 1 h at room temperature, a further amount of 0.2 ml (2.3mmol) 2-methoxyethylamine is added and stirring is continued for 1 h.The reaction mixture is extracted with saturated aqueous sodiumhydrogencarbonate, the organic phase is separated, dried over anhydrousmagnesium sulphate and evaporated. Purification of the residue by columnchromatography on silica gel using dichloromethane:methanol (20:1) andcrystallization from methanol/diethyl ether yields 0.9 g (56%) of thetitle compound as a colourless solid (m.p. 190-191° C.).

4.8-(trans-2,3-Dihydro-2-hydroxy-1-indenylamino)-6-(N,N-dimethylamino-carbonyl)-2,3-dimethyl-imidazo[1,2-a]pyridine

3.0 g (8.9mmol)-8-(trans-2,3-dihydro-2-hydroxy-1-indenylamino)-2,3-dimethyl-imidazo[1,2-a]pyridine-6-carboxylicacid and 3.7 g (11.6 mmol)—O-(1H-benzotriazol-1-yl)-N,N,N′,N′-tetramethyluronium tetrafluoroborate(TBTU) are suspended in 150 ml dichloromethane and 3.2 ml (17.8 mmol)dimethylamine (5.6 M in ethanol) are added to the reaction mixture.After stirring for 16 h at room temperature, the reaction mixture isextracted with saturated aqueous sodium hydrogencarbonate. The organicphase is separated, dried over anhydrous magnesium sulphate andevaporated. The residue is dissolved in 10 ml dichloromethane and 50 mldiethyl ether are added. After stirring for 30 min, the precipitate iscollected, washed with diethyl ether and dried in vacuo to give 2.35 g(73%) of the title compound as a colourless solid (m.p. 148-149° C.).

5.8-(trans-2,3-Dihydro-2-hydroxy-1-indenylamino)-6-(N-methylamino-carbonyl)-2,3-dimethyl-imidazo[1,2-a]pyridine

1.0 g (3.0 mmol)8-(trans-2,3-dihydro-2-hydroxy-1-indenylamino)-2,3-dimethyl-imidazo[1,2-a]pyridine-6-carboxylicacid and 1.2 g (3.9 mmol)O-(1H-benzotriazol-1-yl)-N,N,N′,N′-tetramethyluronium tetrafluoroborate(TBTU) are suspended in 50 ml dichloromethane and 0.74 ml (6.0 mmol)methylamine (8 M in ethanol) are added to the reaction mixture. Afterstirring for 3 d at room temperature, the reaction mixture is hydrolyzedwith saturated aqueous sodium hydrogencarbonate and extracted with ethylacetate. The combined organic phases are dried over anhydrous magnesiumsulphate and evaporated. Purification of the residue by columnchromatography on silica gel using dichloromethane:methanol (20:1) andcrystallization from diethyl ether/light petroleum ether yields 0.2 g(20%) of the title compound as a colourless solid (m.p. 143-144° C.).

6.8-(trans-2,3-Dihydro-2-hydroxy-1-indenylamino)-2,3-dimethyl-imidazol-[1,2-a]pyridine-6-carboxamide

3.0 g (8.9 mmol)8-(trans-2,3-dihydro-2-hydroxy-1-indenylamino)-2,3-dimethyl-imidazo[1,2-a]pyridine-6-carboxylicacid and 3.7 g (11.6 mmol)O-(1H-benzotriazol-1-yl)-N,N,N′,N′-tetramethyluronium tetrafluoroborate(TBTU) are suspended in 150 ml dichloromethane and the mixture isstirred 1 h at room temperature. After ammonia gas is passed through theflask for 1.5 h, the reaction mixture is poured into 200 ml saturatedaqueous ammonium chloride. The pH is adjusted to pH=7 by adding 6Nhydrochloric acid and the mixture is extracted with dichloromethane. Onevaporation of the organic phase, the product begins to crystallize andthe precipitate is collected to yield 0.27 g (10%) of the title compoundas a colourless solid (m.p. 162-163° C.).

7. Ethyl 8-hydroxy-2,3-dimethyl-imidazo[1,2-a]pyridine-6-carboxylate

A solution of 8.0 g (24.7 mmol) ethyl8-benzyloxy-2,3-dimethyl-imidazo[1,2-a]pyridine-6-carboxylate in 80 mlethanol is hydrogenated over 0.8 g 10% Pd/C (1 bar H₂) for 24 h. Thecatalyst is filtered off and the filtrate is evaporated. The oilyresidue is crystallized from diethyl ether to give 5.0 g (86%) of thetitle compound as a colourless solid (m.p. 219-221° C.).

8.8-(trans-2,3-Dihydro-2-hydroxy-1-indenyloxy)-2,3-dimethyl-imidazo[1,2-a]pyridine-6-carboxylicacid

To a suspension of 7.3 g (31.2 mmol) ethyl8-hydroxy-2,3-dimethyl-imidazo[1,2-a]pyridine-6-carboxylate and 7.3 g(55.2 mmol) 1,2-epoxyindane in 150 ml methanol and 15 ml water are added8.8 ml triethylamine and the reaction mixture is heated to 50° C. for 20h. After cooling down, 100 ml ethyl acetate are added and theprecipitate is collected by filtration. A second crop of materialcrystallizes from the mother liquor on evaporation. The total amount ofprecipitate is 6.0 g, which is suspended in a mixture of 100 ml dioxaneand 60 ml 2N aqueous sodium hydroxide. After boiling under reflux for 1h, the reaction mixture is evaporated to ⅓ of its volume and dilutedwith 15 ml methanol. The flask is placed in an ice bath and the pH isadjusted to pH=7 by adding 6N hydrochloric acid. After 30 min, the thicksuspension is diluted with 20 ml methanol and filtered by suction. Asecond crop of material is obtained by evaporation of the mother liquor.The total amount of crude product is 6.75 g. Further purification isachieved by filtration over silica gel usingdichloromethane:methanol:acetic acid (13:1:0.2) as eluent.Crystallization from methanol/diethyl ether yields 2.3 g (22%) of thetitle compound as a colourless solid (m.p. 229-231° C.).

9.8-(trans-2,3-Dihydro-2-hydroxy-1-indenyloxy)-6-(N,N-dimethylamino-carbonyl)-2,3-dimethyl-imidazo[1,2-a]pyridine

2.0 g (5.7 mmol)8-(trans-2,3-dihydro-2-hydroxy-1-indenyloxy)-2,3-dimethyl-imidazo[1,2-a]pyridine-6-carboxylicacid and 2.4 g (7.4 mmol)O-(1H-benzotriazol-1-yl)-N,N,N′,N′-tetramethyluronium tetrafluoroborate(TBTU) are suspended in 100 ml dichloromethane and 2.1 ml (11.4 mmol)dimethylamine (5.6 M in ethanol) are added to the reaction mixture.After stirring for 3 h at room temperature, the reaction mixture ishydrolyzed with saturated aqueous sodium hydrogen carbonate. The organicphase is separated and the aqueous layer is extracted withdichloromethane The combined organic phases are dried over anhydrousmagnesium sulphate and evaporated. Purification of the residue by columnchromatography on silica gel using dichloromethane:methanol (20:1) andcrystallization from methanol/light petroleum ether yields 1.18 g (57%)of the title compound as a colourless solid (m.p. 182-184° C.).

10. 8-Hydroxy-6-methoxymethyl-2,3-dimethyl-imidazo[1,2-a]pyridine

A solution of 3.0 g (10.1 mmol)8-benzyloxy-6-methoxymethyl-2,3-dimethyl-imidazo[1,2-a]pyridine in 50 mlethanol is hydrogenated over 0.3 g 10% Pd/C (1 bar H₂) for 1 h. Thecatalyst is filtered off and the filtrate is evaporated. The residue iscrystallized from methanol/diethyl ether to give 1.2 g (57%) of thetitle compound as a colourless solid (m.p. 164-165° C.).

11.8-(trans-2,3-Dihydro-2-hydroxy-1-indenyloxy)-6-methoxymethyl-2,3-dimethyl-imidazo[1,2-a]pyridine

To a suspension of 1.0 g (4.9 mmol)8-hydroxy-6-methoxymethyl-2,3-dimethyl-imidazo[1,2-a]pyridine and 1.3 g(9.7 mmol) 1,2-epoxyindane in 12 ml methanol and 3 ml water are added1.4 ml triethylamine and the mixture is heated to 50° C. for 24 h. Aftercooling down, the reaction mixture is poured into 100 ml saturatedaqueous ammonium chloride and extracted with dichloromethane. Theorganic phase is dried over anhydrous magnesium sulphate and evaporated.Purification of the residue by column chromatography on silica gel usingdichloromethane:methanol (20:1) yields 0.7 g (45%) of the title compoundas a colourless solid (m.p. 142-143° C.).

12.8-Benzyloxy-6-(N,N-dimethylamino-carbonyl)-2,3-dimethyl-imidazo[1,2-a]pyridine

To a solution of 51.5 g (155 mmol)8-benzyloxy-6-bromo-1,2-dimethyl-imidazo[1,2-a]pyridine in 300 mltetrahydrofuran and 50 ml triethylamine are added 5.15 g (23 mmol)palladium(II) acetate, 24 g (92 mmol) triphenylphosphine and 800 mldimethylamine (2 M in tetrahydrofuran). The mixture is transferred to anautoclave and carbonylated (6-10 bar carbon monoxide pressure, 120° C.)for 16 h. The reaction mixture is cooled down, filtered and evaporated.The residue is dissolved in dichloromethane, extracted with water andevaporated. Purification of the residue by column chromatography onsilica gel using dichloromethane:methanol (13:1) yields 41 g (81%) ofthe title compound as a colourless solid (m.p. 160° C.).

13.6-(N,N-Dimethylaminocarbonyl)8-hydroxy-2,3-dimethyl-imidazo[1,2a]pyridine

A mixture of 40 g (124 mmol)8-benzyloxy-6-(N,N-dimethylaminocarbonyl)-2,3-dimethyl-imidazo[1,2-a]pyridine,15 ml (154 mmol) 1,4-cyclohexadiene and 4 g 10% Pd/C in 400 ml ethanolis heated to reflux. After 3 h, the reaction mixture is cooled down,diluted with 400 ml dichloromethane and filtered. On evaporation, aprecipitate is formed which is collected and dried in vacuo to give 24.5g (85%) of the title compound as a colourless solid (m.p. 278-279° C.).

14.8-[(1S,2S)-2,3-Dihydro-2-hydroxy-1-indenyloxy)-6-(N,N-dimethylamino-carbonyl)-2,3-dimethyl-imidazo[1,2-a]pyridine

To a solution of 1.5 g (6.4 mmol)6-(N,N-dimethylamino-carbonyl)-8-hydroxy-2,3-dimethyl-imidazo[1,2-a]pyridinein 30 ml ethanol and 7.5 ml water are added 1.7 g (12.9 mmol)(1R,2S)-epoxyindane and 1.8 ml triethylamine. After 3 h at 70° C., themixture is cooled down and partitioned between dichloro-methane andwater. The organic layer is separated, dried over anhydrous magnesiumsulphate and evaporated. Purification of the residue by columnchromatography on silica gel using ethyl acetate:light petroleum ether(1:1) and crystallization from diisopropyl ether yields 1.7 g (74%) ofthe title compound as a colourless solid (m.p. 122° C.).

15.6-(N,N-Dimethylamino-carbonyl)-2,3-dimethyl-8-(trans-1,2,3,4-tetrahydro-2-hydroxy-1-naphthalenyloxy)-imidazo[1,2-a]pyridinehydrochloride

To a solution of 1.0 g (4.3 mmol)6-(N,N-dimethylamino-carbonyl)-8-hydroxy-2,3-dimethyl-imidazo[1,2-a]pyridinein 20 ml ethanol and 5 ml water are added 1.25 g (8.6 mmol)1,2-epoxy-1,2,3,4-tetrahydro-naphthalene and 1.2 ml triethylamine. After16 h at 80° C., the mixture is cooled down and partitioned betweendichloromethane and saturated aqueous ammonium chloride. The organiclayer is separated, dried over anhydrous magnesium sulphate andevaporated. Purification of the residue is achieved by columnchromatography on silica gel using ethyl acetate:light petroleum ether(1:1), then dichloro-methane:methanol (20:1). The oil thus obtained isdissolved in ethyl acetate and treated with saturated hydrogen chloridein diethyl ether to give a precipitate which is collected and dried toyield 0.6 g (34%) of the title compound as a colourless solid (m.p. 129°C.).

16.8-(trans-2,3-Dihydro-2-hydroxy-7-methoxy-1-indenyloxy)-6-(N,N-dimethylamino-carbonyl)-2,3-dimethyl-imidazo[1,2-a]pyridine

To a solution of 0.8 g (3.4 mmol)6-(N,N-dimethylamino-carbonyl)-8-hydroxy-2,3-dimethyl-imidazo[1,2-a]pyridinein 16 ml ethanol and 4 ml water are added 1.0 g (6.2 mmol)1,2-epoxy-7-methoxy-indane and 0.48 ml triethylamine. After 4 h at 30°C., the mixture is cooled down and partitioned between di-chloromethaneand saturated aqueous ammonium chloride. The organic layer is separated,dried over anhydrous magnesium sulphate and evaporated. Purification ofthe residue by column chromatography on silica gel using ethylacetate:light petroleum ether:triethylamine (8:1:1) yields 0.26 g (19%)of the title compound as a colourless solid (m.p. 129° C.).

17.8-(tans-2,3-Dihydro-2-hydroxy-7-methyl-1-indenyloxy)-6-(N,N-dimethylamino-carbonyl)-2,3-dimethyl-imidazo1,2-a]pyridine

To a solution of 0.8 g (3.4 mmol)6-(N,N-dimethylamino-carbonyl)-8-hydroxy-2,3-dimethyl-imidazo[1,2-a]pyridinein 16 ml ethanol and 4 ml water are added 0.9 g (1.2 mmol)1,2-epoxy-7-methyl-indane and 0.48 ml triethylamine. After 5 h at 30°C., the mixture is cooled down and partitioned between ethyl acetate andsaturated aqueous ammonium chloride. The organic layer is separated,dried over anhydrous magnesium sulphate and evaporated. Purification ofthe residue by column chromatography on silica gel using ethylacetate:light petroleum ether:triethylamine (8:1:1) and crystallizationfrom ethyl acetate/diethyl ether yields 0.26 g (20%) of the titlecompound as a colourless solid (m.p. 198° C.).

Commercial Utility

The compounds of the formula 1 and their salts have valuablepharmacological properties which make them commercially utilizable. Inparticular, they exhibit marked inhibition of gastric acid secretion andan excellent gastric and intestinal protective action in warm-bloodedanimals, in particular humans. In this connection, the compoundsaccording to the invention are distinguished by a high selectivity ofaction, an advantageous duration of action, a particularly good enteralactivity, the absence of significant side effects and a largetherapeutic range.

“Gastric and intestinal protection” in this connection is understood asmeaning the prevention and treatment of gastrointestinal diseases, inparticular of gastrointestinal inflammatory diseases and lesions (suchas, for example, gastric ulcer, duodenal ulcer, gastritis, hyperacidicor medicament-related functional dyspepsia), which can be caused, forexample, by microorganisms (e.g. Helicobacter pylori), bacterial toxins,medicaments (e.g. certain antiinflammatories and antirheumatics),chemicals (e.g. ethanol), gastric acid or stress situations.

In their excellent properties, the compounds according to the inventionsurprisingly prove to be clearly superior to the compounds known fromthe prior art in various models in which the antiulcerogenic and theantisecretory properties are determined. On account of these properties,the compounds of the formula 1 and their pharmacologically acceptablesalts are outstandingly suitable for use in human and veterinarymedicine, where they are used, in particular, for the treatment and/orprophylaxis of disorders of the stomach and/or intestine.

A further subject of the invention are therefore the compounds accordingto the invention for use in the treatment and/or prophylaxis of theabovementioned diseases.

The invention likewise includes the use of the compounds according tothe invention for the production of medicaments which are employed forthe treatment and/or prophylaxis of the abovementioned diseases.

The invention furthermore includes the use of the compounds according tothe invention for the treatment and/or prophylaxis of the abovementioneddiseases.

A further subject of the invention are medicaments which comprise one ormore compounds of the formula 1 and/or their pharmacologicallyacceptable salts.

The medicaments are prepared by processes which are known per se andfamiliar to the person skilled in the art. As medicaments, thepharmacologically active compounds according to the invention (=activecompounds) are either employed as such, or preferably in combinationwith suitable pharmaceutical auxiliaries or excipients in the form oftablets, coated tablets, capsules, suppositories, patches (e.g. as TTS),emulsions, suspensions or solutions, the active compound contentadvantageously being between 0.1 and 95% and it being possible to obtaina pharmaceutical administration form exactly adapted to the activecompound and/or to the desired onset and/or duration of action (e.g. asustained-release form or an enteric form) by means of the appropriateselection of the auxiliaries and excipients.

The auxiliaries and excipients which are suitable for the desiredpharmaceutical formulations are known to the person skilled in the arton the basis of his/her expert knowledge. In addition to solvents,gel-forming agents, suppository bases, tablet auxiliaries and otheractive compound excipients, it is possible to use, for example,antioxidants, dispersants, emulsifiers, antifoams, flavor corrigents,preservatives, solubilizers, colorants or, in particular, permeationpromoters and complexing agents (e.g. cyclodextrins).

The active compounds can be administered orally, parenterally orpercutaneously.

In general, it has proven advantageous in human medicine to administerthe active compound(s) in the case of oral administration in a dailydose of approximately 0.01 to approximately 20, preferably 0.05 to 5, inparticular 0.1 to 1.5, mg/kg of body weight, if appropriate in the formof several, preferably 1 to 4, individual doses to achieve the desiredresult. In the case of a parenteral treatment, similar or (in particularin the case of the intravenous administration of the active compounds),as a rule, lower doses can be used. The establishment of the optimaldose and manner of administration of the active compounds necessary ineach case can easily be carried out by any person skilled in the art onthe basis of his/her expert knowledge.

If the compounds according to the invention and/or their salts are to beused for the treatment of the abovementioned diseases, thepharmaceutical preparations can also contain one or morepharmacologically active constituents of other groups of medicaments,for example: tranquillizers (for example from the group of thebenzodiazepines, for example diazepam), spasmolytics (for example,bietamiverine or camylofine), antcholinergics (for example,oxyphencyclimine or phencarbamide), local anesthetics, (for example,tetracaine or procaine), and, if appropriate, also enzymes, vitamins oramino acids.

To be emphasized in this connection is in particular the combination ofthe compounds according to the invention with pharmaceuticals whichinhibit acid secretion, such as, for example, H₂ blockers (e.g.cimetidine, ranitidine), H⁺/K⁺ ATPase inhibitors (e.g. omeprazole,pantoprazole), or further with so-called peripheral anticholinergics(e.g. pirenzepine, telenzepine) and with gastrin antagonists with theaim of increasing the principal action in an additive or super-additivesense and/or of eliminating or of decreasing the side effects, orfurther the combination with antibacterially active substances (such as,for example, cephalosporins, tetracyclines, penicillins, macrolides,nitroimidazoles or alternatively bismuth salts) for the control ofHelicobacter pylori. Suitable antibacterial co-components which may bementioned are, for example, mezlocillin, ampicillin, amoxicillin,cefalothin, cefoxitin, cefotaxime, imipenem, gentamycin, amikacin,erythromycin, ciprofloxacin, metronidazole, clarithromycin, azithromycinand combinations thereof (for example clarithromycin+metronidazole).

In view of their excellent gastric and intestinal protection action, thecompounds of formula 1 are suited for a free or fixed combination withthose medicaments (e.g. certain antiinflammatories and antirheumatics,such as NSAIDs), which are known to have a certain ulcerogenic potence.In addition, the compounds of formula 1 are particularly suited for afree or fixed combination with motility-modifying drugs.

Pharmacology

The excellent gastric protection and the gastric acidsecretion-inhibiting action of the compounds according to the inventioncan be demonstrated in investigations on animal experimental models. Thecompounds according to the invention investigated in the model mentionedbelow have been provided with numbers which correspond to the numbers ofthese compounds in the examples.

Testing of the Secretion-Inhibiting Action on the Perfused Rat Stomach

In Table A which follows, the influence of the compounds according tothe invention on the pentagastrin-stimulated acid secretion of theperfused rat stomach after intraduodenal administration in vivo isshown.

TABLE A Dose Inhibition of No. (μmol/kg) i.d. acid secretion (%) 9 1 >3011 1 >30 14 1 >30 15 1 >30 16 1 >30 17 1 >30Methodology

The abdomen of anaesthetized rats (CD rat, female, 200-250 g; 1.5 g/kgi.m. urethane) was opened after tracheotomy by a median upper abdominalincision and a PVC catheter was fixed transorally in the oesophagus andanother via the pylorus such that the ends of the tubes just projectedinto the gastric lumen. The catheter leading from the pylorus ledoutward into the right abdominal wall through a side opening.

After thorough rinsing (about 50-100 ml), warm (37° C.) physiologicalNaCl solution was continuously passed through the stomach (0.5 ml/min,ph 6.8-6.9; Braun-Unita I). The pH (pH meter 632, glass electrode EA147; φ=5 mm, Metrohm) and, by titration with a freshly prepared 0.01NNaOH solution to ph 7 (Dosimat 665 Metrohm), the secreted HCl weredetermined in the effluent in each case collected at an interval of 15minutes.

The gastric secretion was stimulated by continuous infusion of 1 μg/kg(=1.65 ml/h) of i.v. pentagastrin (left femoral vein) about 30 min afterthe end of the operation (i.e. after determination of 2 preliminaryfractions). The substances to be tested were administeredintraduodenally in a 2.5 ml/kg liquid volume 60 min after the start ofthe continuous pentagastrin infusion.

The body temperature of the animals was kept at a constant 37.8-38° C.by infrared irradiation and heat pads (automatic, stepless control bymeans of a rectal temperature sensor).

1. A compound of the formula 1

in which R1 is hydrogen, 1-4C-alkyl, 3-7C-cycloalkyl,3-7C-cycloalkyl-1-4C-alkyl, 1-4C-alkoxy, 1-4C-alkoxy- 1-4C-alkyl,1-4C-alkoxycarbonyl, 2-4C-alkenyl, 2-4C-alkynyl, fluoro-1-4C-alkyl orhydroxy-1-4C-alkyl, R2 is hydrogen, 1-4C-alkyl, aryl, 3-7C-cycloalkyl,3-7C-cycloalkyl-1-4C-alkyl, 1-4C-alkoxycarbonyl, hydroxy-1-4C-alkyl,halogen, 2-4C-alkenyl, 2-4C-alkynyl, fluoro-1-4C-alkyl,1-4C-alkyl-aminomethyl or cyanomethyl, R3a is hydrogen, halogen,fluoro-1-4C-alkyl, 1-4C-alkyl, 2-4C-alkenyl, 2-4C-alkynyl, carboxyl,—CO-1-4C-alkoxy, hydroxy-1-4C-alkyl, 1-4C-alkoxy-1-4C-alkyl,1-4C-alkoxy-1-4C-alkoxy-1-4C-alkyl, fluoro-1-4C-alkoxy-1-4C-alkyl or thegroup —CO—NR31R32, R3b is hydrogen, halogen, fluoro-1-4C-alkyl,1-4C-alkyl, 2-4C-alkenyl, 2-4C-alkynyl, carboxyl, —CO- 1-4C-alkoxy,hydroxy-1-4C-alkyl, 1-4C-alkoxy-1-4C-alkyl,1-4C-alkoxy-1-4C-alkoxy-1-4C-alkyl, fluoro-1-4C-alkoxy-1-4C-alkyl or thegroup —CO—NR31R32, where R31 is hydrogen, hydroxyl, 1-7C-alkyl,hydroxy-1-4C-alkyl or 1-4C-alkoxy-1-4C-alkyl and R32 is hydrogen,1-7C-alkyl, hydroxy-1-4C-alkyl or 1-4C-alkoxy-1-4C-alkyl, or where R31and R32 together, including the nitrogen atom to which both are bonded,are a pyrrolidino, piperidino, piperazino, N-1-4C-alkylpiperazino ormorpholino group, Z has the meaning —CHR4- or —CHR4-CHR5- where R4 ishydrogen, 1-7C-alkyl, 2-7C-alkenyl, hydroxyl, 1-4C-alkoxy,oxo-substituted 1-4C-alkoxy, 3-7C-cycloalkoxy,3-7C-cycloalkyl-1-4C-alkoxy, hydroxy-1-4C-alkoxy,1-4C-alkoxy-1-4C-alkoxy, 1-4C-alkoxy-1-4C-alkoxy-1-4C-alkoxy,3-7C-cycloalkoxy-1-4C-alkoxy, 3-7C-cycloalkyl-1-4C-alkoxy-1-4C-alkoxy,1-4C-alkylcarbonyloxy, halo-1-4C-alkoxy, amino, mono- ordi-1-4C-alkylamino, 1-4C-alkylcarbonylamino, 1-4C-alkoxycarbonylamino,mono- or di-1-4C-alkylamino-1-4C-alkylcarbonyloxy or1-4C-alkoxy-1-4C-alkoxycarbonylamino, R5 is hydrogen, 1-7C-alkyl,2-7C-alkenyl, hydroxyl, 1-4C-alkoxy, oxo-substituted 1-4C-alkoxy,3-7C-cycloalkoxy, 3-7C-cycloalkyl-1-4C-alkoxy, hydroxy-1-4C-alkoxy,1-4C-alkoxy-1-4C-alkoxy, 1-4C-alkoxy-1-4C-alkoxy-1-4C-alkoxy,3-7C-cycloalkoxy-1-4C-alkoxy, 3-7C-cycloalkyl-1-4C-alkoxy-1-4C-alkoxy,1-4C-alkylcarbonyloxy, halo-1-4C-alkoxy, amino, mono- ordi-1-4C-alkylamino, 1-4C-alkylcarbonylamino, 1-4C-alkoxycarbonylamino,mono- or di-1-4C-alkylamino-1-4C-alkylcarbonyloxy or1-4C-alkoxy-1-4C-alkoxycarbonylamino, R6 is hydrogen, 1-4C-alkyl,hydroxy-1-4C-alkyl, 1-4C-alkoxy, 1-4C-alkoxy-1-4C-alkyl,2-4C-alkenyloxy, 1-4C-alkylcarbonyl, carboxyl, 1-4C-alkoxycarbonyl,carboxy-1-4C-alkyl, 1-4C-alkoxycarbonyl-1-4C-alkyl, halogen, hydroxyl,trifluoromethyl, nitro, amino, mono- or di-1-4C-alkylamino,1-4C-alkylcarbonylamino, 1-4C-alkoxycarbonylamino,1-4C-alkoxy-1-4C-alkoxycarbonylamino or sulfonyl, R7 is hydrogen,1-4C-alkyl, 1-4C-alkoxy, 1-4C-alkoxycarbonyl, halogen, trifluoromethylor hydroxyl, X is O (oxygen) or NH, and aryl is phenyl or substitutedphenyl having one, two or three identical or different substituents fromthe group consisting of 1-4C-alkyl, 1-4C-alkoxy, carboxyl,1-4C-alkoxycarbonyl, halogen, trifluoromethyl, nitro, trifluoromethoxy,hydroxyl and cyano, or a salt thereof, with the provisos that (1) R3a isnot hydrogen, halogen, 1-4C-alkoxy or —CO-1-4C-alkoxy when R3b ishydrogen, Z has the meaning —CHR4- and R4 is hydrogen or 1-7C-alkyl, (2)R3a is not hydrogen, halogen, 1-4C-alkoxy or —CO-1-4C-alkoxy when R3b ishydrogen, Z has the meaning —CHR4-CHR5-, R4 is hydrogen or 1-7C-alkyland R5 is hydrogen or 1-7C-alkyl, (3) R3a is not hydrogen or halogenwhen R3b is hydrogen, Z has the meaning —CHR4- and R4 is hydroxyl, (4)R3a is not hydrogen or halogen when R3b is hydrogen, Z has the meaning—CHR4-CHR5-, one of R4 and R5 is hydroxyl and the other is hydrogen or1-7C-alkyl, (5) R3a is not hydrogen when R3b is hydrogen, X is O(oxygen), Z has the meaning —CHR4- and R4 is 1-4C-alkoxy,3-7C-cycloalkoxy, 1-4C-alkoxy-1-4C-alkoxy or 1-4C-alkylcarbonyloxy and(6) R3a is not hydrogen when R3b is hydrogen, X is O (oxygen), Z has themeaning —CHR4-CHR5-, one of R4 and R5 1-4C-alkoxy, 3-7C-cycloalkoxy,1-4C-alkoxy-1-4C-alkoxy or 1-4C-alkylcarbonyloxy and the other ishydrogen.
 2. A compound of the formula 1 according to claim 1, in whichZ has the meaning —CHR4- and which is characterized by the formula 1-1

in which R1, R2, R3a, R3b, R4, R6, R7 and X have the meanings given inclaim 1, or a salt thereof.
 3. A compound of the formula 1 according toclaim 1, in which Z has the meaning —CHR4-CHR5- and which ischaracterized by the formula 1-2

in which R1, R2, R3a, R3b, R4, R5, R6, R7 and X have the meanings givenin claim 1, or a salt thereof.
 4. A compound of formula 1 according toclaim 1, in which R1 is 1-4C-alkyl, R2 is hydrogen, 1-4C-alkyl orhalogen, R3a is in the 6-position and denotes carboxyl, —CO-1-4C-alkoxy,hydroxy-1-4C-alkyl, 1-4C-alkoxy-1-4C-alkyl or the group —CO—NR31R32,where R31 is hydrogen, 1-7C-alkyl, hydroxy-1-4C-alkyl or1-4C-alkoxy-1-4C-alkyl and R32 is hydrogen, 1-7C-alkyl,hydroxy-1-4C-alkyl or 1-4C-alkoxy-1-4C-alkyl, or where R31 and R32together, including the nitrogen atom to which both are bonded, are apyrrolidino, piperidino, piperazino, N-1-4C-alkylpiperazino ormorpholino group, R3b is hydrogen, Z has the meaning —CHR4- or—CHR4-CHR5- where R4 is hydroxyl, R5 is hydrogen, R6 is hydrogen,1-4C-alkyl or 1-4C-alkoxy, R7 is hydrogen, X is O (oxygen) or NH, or asalt thereof.
 5. A compound of formula 1-1 according to claim 2, inwhich R1 is 1-4C-alkyl, R2 is hydrogen, 1-4C-alkyl or halogen, R3a is inthe 6-position and denotes carboxyl, —CO-1-4C-alkoxy,hydroxy-1-4C-alkyl, 1-4C-alkoxy-1-4C-alkyl or the group —CO—NR31R32,where R31 is hydrogen, 1-7C-alkyl, hydroxy-1-4C-alkyl or1-4C-alkoxy-1-4C-alkyl and R32 is hydrogen, 1-7C-alkyl,hydroxy-1-4C-alkyl or 1-4C-alkoxy-1-4C-alkyl, or where R31 and R32together, including the nitrogen atom to which both are bonded, are apyrrolidino, piperidino, piperazino, N-1-4C-alkylpiperazino ormorpholino group, R3b is hydrogen, R4 is hydroxyl, R6 is hydrogen,1-4C-alkyl or 1-4C-alkoxy, R7 is hydrogen, X is O (oxygen) or NH, or asalt thereof.
 6. An optically pure compound of formula 1-1 according toclaim 2, which is characterized by the formula 1-1*

and in which R1 is 1-4C-alkyl, R2 is hydrogen, 1-4C-alkyl or halogen,R3a is in the 6-position and denotes carboxyl, —CO-1-4C-alkoxy,1-4C-alkoxy-1-4C-alkyl, 1-4C-alkoxy-1-4C-alkoxy-1-4C-alkyl or the group—CO—NR31R32, where R31 is hydrogen, 1-7C-alkyl, hydroxy-1-4C-alkyl or1-4C-alkoxy-1-4C-alkyl and R32 is hydrogen, 1-7C-alkyl,hydroxy-1-4C-alkyl or 1-4C-alkoxy-1-4C-alkyl, or where R31 and R32together, including the nitrogen atom to which both are bonded, are apyrrolidino, piperidino, piperazino, N-1-4C-alkylpiperazino ormorpholino group, R4 is hydroxyl, 1-4C-alkoxy, oxo-substituted1-4C-alkoxy, 3-7C-cycloalkoxy, 3-7C-cycloalkyl-1-4C-alkoxy,hydroxy-1-4C-alkoxy, 1-4C-alkoxy-1-4C-alkoxy,1-4C-alkoxy-1-4C-alkoxy-1-4C-alkoxy, 3-7C-cycloalkoxy-1-4C-alkoxy,3-7C-cycloalkyl-1-4C-alkoxy-1-4C-alkoxy, 1-4C-alkylcarbonyloxy,halo-1-4C-alkoxy, amino, mono- or di-1-4C-alkylamino,1-4C-alkylcarbonylamino, 1-4C-alkoxycarbonylamino, mono- ordi-1-4C-alkylamino-1-4C-alkylcarbonyloxy or1-4C-alkoxy-1-4C-alkoxycarbonylamino, R6 is hydrogen, 1-4C-alkyl,1-4C-alkoxy or halogen, R7 is hydrogen, X is O (oxygen) or NH, or a saltthereof.
 7. A compound of formula 1-1* according to claim 6, in which R1is 1-4C-alkyl, R2 is 1-4C-alkyl, R3a is in the 6-position and denotescarboxyl, —CO-1-4C-alkoxy, 1-4C-alkoxy-1-4C-alkyl or the group—CO—NR31R32, where R31 is hydrogen, 1-4C-alkyl, hydroxy-1-4C-alkyl or1-4C-alkoxy-1-4C-alkyl and R32 is hydrogen or 1-4C-alkyl, R4 ishydroxyl, R6 is hydrogen, R7 is hydrogen, X is O (oxygen) or NH, or asalt thereof.
 8. An optically pure compound of formula 1-2 according toclaim 3, which is characterized by the formula 1-2*

in which R1 is 1-4C-alkyl, R2 is 1-4C-alkyl, R3a is in the 6-positionand denotes carboxyl, —CO-1-4C-alkoxy, 1-4C-alkoxy-1-4C-alkyl or thegroup —CO—NR31R32, where R31 is hydrogen, 1-4C-alkyl, hydroxy-1-4C-alkylor 1-4C-alkoxy-1-4C-alkyl and R32 is hydrogen or 1-4C-alkyl, R4 ishydroxyl, R5 is hydrogen, R6 is hydrogen, R7 is hydrogen, X is O(oxygen) or NH, or a salt thereof.
 9. A pharmaceutical compositioncomprising a therapeutically effective amount of a compound as claimedin claim 1 and/or a pharmaceutically acceptable salt thereof, togetherwith a pharmaceutically acceptable auxiliary and/or excipient.
 10. Amethod of treating a gastrointestinal disorder caused by gastric acid ina patient comprising administering to a patient in need thereof acompound of formula I as claimed in claim 1, or a pharmaceuticallyacceptable salt thereof.
 11. A compound of the formula I, selected fromthe group consisting of Methyl8-(trans-2,3-dihydro-2-hydroxy-1-indenylamino)-2,3-dimethyl-imidazo[1,2a]pyridine-6-carboxylate,8-(trans-2,3-Dihydro-2-hydroxy-1-indenylamino)-2,3-dimethyl-imidazo[1,2-a]pyridine-6-carboxylicacid,8-(trans2,3-Dihydro-2-hydroxy-1-indenylamino)-6-[N-(2-methoxyethyl)-amino-carbonyl]-2,3-dimethyl-imidazo[1,2-a]pyridine,8-(trans-2,3-Dihydro-2-hydroxy-1-indenylamino)-6-(N,N-dimethylaminocarbonyl)-2,3-dimethyl-imidazo[1,2-a]pyridine,8-(trans-2,3-Dihydro-2-hydroxy-1-indenylamino)-6-(N-methylamino-carbonyl)-2,3-dimethyl-imidazo[1,2-a]pyridine,8-(trans2,3-Dihydro-2-hydroxy-1-indenylamino)-2,3-dimethy-imidazo[1,2-a]pyridine-6-carboxamide,8-(trans-2,3-Dihydro-2-hydroxy-1-indenyloxy)-2,3-dimethyl-imidazo[1,2a]pyridine-6-carboxylicacid,8-(trans-2,3-Dihydro-2-hydroxy-1-indenyloxy)-6-(N,N-dimethylamino-carbonyl)-2,3-dimethyl-imidazo[1,2-a]pyridine,8-(trans-2,3-Dihydro-2-hydroxy-1-indenyloxy)-6-methoxymethyl-2,3-dimethyl-imidazo[1,2-a]pyridine,8-[(1S,2S)-2,3-Dihydro-2-hydroxy-1-indenyloxy)-6-(N,N-dimethylamino-carbonyl)-2,3-dimethyl-imidazo[1,2-a]pyridine,6-(N,N-Dimethylamino-carbonyl)-2,3-dirnethyl8-(trans-1,2,3,4-tetrahydro-2hydroxy-1naphthalenyloxy)-imidazo[1,2a]pyridinehydrochloride,8-(trans-2,3-Dihydro-2hydroxy-7-methoxy-1-indenyloxy)-6-(N,N-dimethylamino-carbonyl)-2,3-dimethylimidazo[1,2-a]pyridine,and8-(trans2,3-Dihydro-2-hydroxy-7-methyl-1-indenyloxy)-6-(N,N-dimethylaminocarbonyl)-2,3-dimethyl-imidazo[1,2-a]pyridineand salt thereof.
 12. A method of treating a gastrointestinal disordercaused by gastric acid in a patient comprising administering to apatient in need thereof a compound of formula I as claimed in claim 1,or a pharmaceutically acceptable salt thereof, wherein the disorder isselected from the group consisting of gastric ulcer, duodenal ulcer,gastritis, hyperacidic related functional gastropathy, medicinallyrelated functional gastropathy, reflux esophagitis, Zollinger-Ellisonsyndrome, heartburn and peptic ulcer bleeding.